Air conditioning apparatus



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P. KOMROFF ET AL AIR CONDITIONING APPARATUS 6 Sheets-Sheetl 6 Filed Aug. 7, 1957 Patented Aug. 2o, 1940 IUNITED STATES PATENT OFFICE AIR CONDITIONING APPARATUS Delaware Application August 1, 1937, serial No. 157,866

31 Claims.

Our invention relates to control devices and systems, and more particularly to control systems for air conditioning apparatus.

The invention consists in the novel construction, combination and arrangement of parts, to

be more fully described hereinafter, and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawings, to be taken as a part of this specication, we have fully and -clearly illustrated a preferred embodimentof our invention, in which drawings- Fig. l is a longitudinal vertical section through an air conditioning unit, the operation of which l5 is-controlled by our improved system.

Fig. 2 is a transverse vertical section taken on the line 2-2 of Fig. 1.

Fig. 3 is a transverse'vertical section taken on the line 3 3 of Fig. 1.

Fig. 4 is a horizontal plan section taken on the broken line 4-4 of Fig. 2.

Fig. 5 is an enlarged fragmentary vertical section taken on the lineS-- of Fig. 4.

Fig. 6 is a diagrammatic view illustrating all of the electrical control circuits used in our control system. and indicating by heavy black lines the particular circuits in use during the summer or hot months when automatic control of the room temperature is desired.

Fig. 7 is a view similar to Fig. 6, and indicating by heavy black lines the particular circuits in use during the summer when the room temperature is manually regulated.

Fig. 8 is a diagrammatic view like Fig. 6, and

35 indicating by heavy black lines the electrical circuits in use during the winter or colder months when it is desired to regulate automatically the room temperature.

Fig. 9 is a view like Fig. 8, and indicating by o heavy black lines the operation of the air conditioning apparatus during the winter when it is desired to control manually the room temperature.

Fig. l0 is also a diagrammatic view illustrating the circuits of our control system, and indicating by heavy black lines the circuits in use during mild weather when only fresh, clean air is desired in the room.

50 Fig. 11 is a detail plan view showing one preferred arrangement of switches for effecting the operation of the various electrical circuits.

Fig. 12 is a view illustrating diagrammatically the three diierent positions which each of the two control switches illustrated in Fig. 11 occupy for the different operations provided by our system.

Referring now in detail to the construction illustrated. it will be observed that we have shown our invention as embodied in an air conditioning 5 unit of the type which is adapted to be installed in a room space and which operates to provide healthful and comfortable conditions in the room space throughout all seasons of the year. l

Referring ilrst to Figs. 1 to 5 inclusive, the air 10 conditioning unit is indicated in general by the reference character I0, and comprises a central section Il and wing sections I2 and yI3 arranged respectively at the ends of the .central section. In the top wall of the central section is provided 15 an air inlet I4 which extends for the full length of the central section and communicates with the room space. In the upper-rear part of the central section is provided a second air inlet I5 which communicates with the outdoors through a rear- 20 wardly extending horizontal duct I6. 'Ihe duct I8 is adapted to be arranged between the lower sash rail and the window sill of a window (not shown), and is of the same length as the central section II, and is lined interiorly with suitable 2l sound absorbing material, indicated at Il. The top wall of the central section II is also provided with an air outlet I8 which communicates with the room space. The air outlet I8 is of substantially the same size as the room air inlet I4 and 30 also extends for the full length of the central section I I.

The room air inlet I4 and room air outlet I8 are provided with suitable removable grilles I8 and 20, respectively; the grille 28 being conas structed to direct the air upwardly and forwardly of the unit and into `the room (see Fig. 2).

Connecting the inlets I4 and I5 and outlet 28 is a U-shaped air passage 2I which is defined by the walls of the central section II and also 4 by a partition means 22 which depends from the top wall of the central section between the inlet and outlet openings I4 and I8 and terminates short of the'bottom of the section to provide the return-bend portion of the AU-shaped passage. 'I'he direction of air flow is indicated by the arrows in Fig. 2.

A motor-driven blower 28 is arranged in the lower part of the upgoing leg of the passage 2I and is arranged to draw air into the passage through the inlets I4 and I 5 and to discharge such air upwardly through the outlet opening I8 and into the room space. 'A damper 24 is arranged between the inlet openings I4 and I8. `The damper 24 is ilxed at its upper edge to a 55 horizontal shaft 24a which is in turn journalled in the defining end walls of the passage 2l so as to provide pivotal movement of the damper about a horizontalaxis. The damper 24 extends for the length of the central section and serves to proportion the amounts of room air and outdoor air drawn into the unit by the blower.

In operation, the damper 24 may be moved by hand to a selected position so that desired amounts of fresh and room air are drawn into the passage 2|, and it may be moved by electrically operated means between this preselected open position and the positionwhere it closes entirely the outdoor air inlet I5, for a. purpose which will presently appear.

The mechanism for operating the damper 24 is indicated generally by the reference character 25, and includes a longitudinally movable operating rod 26, a link 21, a connecting link 28, and

a connecting tension spring 29 (see Figs.-4 and The rod 26 is mounted for lengthwise movement in a guide opening 30 provided in a flange 3l depending from the top wallof the duct I6, and in a guide opening 32 formed in the front wall of the duct I6 and aligned with the opening 30. .The forward end of the rod 26 is provided with a knob 33 adapted to be grasped by the hand for effecting its lengthwise movement. The under surface of the forward part of the rod is provided with a series of notches 34 which are adapted to receive the bottom edge of the opening 32 and thereby hold the rod 26 at any preselected position. IThe forward end of the link 21 is pivotally connected by a pin 35 to flanges 36 fixed to the damper 24, and the rear part of the link 21 is connected by a pin 31 and slot 38 to the lower end of the connecting link 2,8. The upper end of the link 28 is pivotally connected by a pin 39 to the rear end of the rod 26. An abutment 40 is fixed to the link 28 and engages the lower end of an adjusting screw 4I on the rod 26. The tension spring 29 connects the rod 26 and link 21 at points spaced forwardly from the link 28 and is inclined downwardly and rearwardly so as to pull the links 21 and 28 forwardly and hold the abutment 40 against the screw 4|, so that by moving the rod 26 forwardly and rearwardly by hand, the links 21 and 28 andl damper 24 will move as a unit with the rod 26. Thus the damper 24 may be set by hand at any desired position to proportion the amounts of outdoor and room air entering the passage.

As stated, the damper-operating mechanism 25 also includes electrically operated means to move the damper from its preselected open position to a position where the outdoor airI inlet I5 is closed. This means includes a flexible chain 42 connected at its forward end to the pin 35 and at its rear end to one outer end of a composite lever arm 43. 'I'he lever arm 43 is fulcrumed at 44 on a housing 45 ixed on the unit I8, and is pivotally connected at its other outer end to the outer end of an operating rod 46 forming a part of a heat motor 41 enclosed by the housing 45. The motor 41 comprises a cylinder 48, a corrugated expansible collapsible element or metallic bellows 49, the rod 46 which is connected at its inner end to the closed end wall of the bellows 49, and a compression spring 58 encircling the rod 46 and tending to extend the bellows 49 and to pull the lever 43 in a clockwise direction as viewed in Fig. 4. The heat motor 41.also includes an electrical heating device 5I which is connected to the interior of the cylinder 48 by a tube 52. The operation is such that when the heating device 5I is energized by the closing of an electrical circuit, an expansible fluid in the tube 52 and cylinder 48 expands and compresses the bellowsl 49, and thereby moves the rod 46 and lever 43 counterclockwise against the force of the spring 50.

'In the drawings, the parts are shown in the positions which they occupy when the heating device is energized. The bellows 49 and spring 50 are shown as compressed, and the full-line position of the lever arm is such that the chain 42 is slack and the damper 24 is at its open position previously selected by hand operation. Should the device 5I become deenergized by the opening of its electrical control circuit, vthe spring 58 will pull the lever 43 to the dotted-line position shown, and the chain 42 will pull the damper 24 and link 21 against the force of the spring 29 to a position where the outdoor air inlet I5 is closed. For the latter part of this movement, the link 28 will move about the pivot pin 39. When the heating device 5I is again energized, the expansible fluid in the cylinder will cause the bellows 49 and rod 46 to move the lever 43 to its full-line position against the force of the spring 58; and, as a result, the chain 42 will be slackened and the spring 29 will pull the link 21 and damper 24 to its preselected open position.

The pin 31 and slot 38 provide lost motion between the links 21 and 28, and thereby permit rearward movement of the rod .26 and link 28 after the damper 24 has been closed by hand. A compression spring 53 abutting at one end the link 28 and at the other end a bolt extending through the rear end of the rod 21, tends to hold the pin 31 against the forward end of the slot 38. This construction permits the rod 26 to be moved inwardly after the damper 24 is closed so that the forward notch 34 may be engaged. Thev spring 53 will then hold the damper 24 tightly closed.

The particular form and arrangement of the damper operating mechanism 25 just described is not in itself a part of the present invention, it having been disclosed and claimed in the copending application of Komroif and Lambert, Serial No. 170,168, filed October 21, 1937. Insovfar as the present invention is concerned, the

mechanism 25 is to be considered as one element of our improved control system, which element functions to control the amount of fresh air entering 'the passage 2| during the different seasons of the year.

Arranged across the upper part of the downcoming leg of the U-shaped passage 2I is a removable flter 55 which serves to remove foreign matter from the air entering the passage. Arranged directly beneath the filter 55 and across the passage 2I is a cooling coil 56 of any suitable construction. In the drawings, the coil 56 is shown as comprising horizontally extending tubes 51 -connected at their ends to provide through circulation of a refrigerant fluid, vertical fins 58 fixed to the exterior of the tubes, and refrigerant supply and return pipes 59 and 68. Liquid refrigerant may be supplied to the pipe 59 ofthe coil from any suitable source, such, for example, as a motor-compressor-condenser unit (not shown). The return pipe 60 may be connected to the suction side of such a unit.

An electrically operated valve 6I of conventional form is provided in the supply pipe 59, and

operates when energized to open and permit ow of refrigerant fluid to the coil 56, and when deenergized, to close and prevent flow of refrigerant tothe coil. When the valve 6I is open, the temperature of the coil is maintained at a substantially constant value by a suitable expansion valve 62 also located in the supply pipe 59 and controlled by a conventional type of thermostatic bulb .63 clamped to the coil 56.

Below the coil 56 and in the lower part of the central section II is arranged a condensate-collecting receptacle 64. Condensate from the coil 56 will gravitate into the receptacle 64 and will be removed therefrom in a manner which will be described presently.

Arranged across the upper part of the upgoing leg of the passage 2| is a suitable heating coil 65, here shown as comprising horizontal pipes 66 and heat radiating ns 61 connecting the pipes. A heating iluid, which may be either steam or hot water, is supplied to the coil 65 by a pipe 68. A4

return pipe 69 serves to conduct away the heating fluid after its passage through the coil. The

`flow of heating uid to the coil may be regulated lby a suitable hand valve in the pipe 68.

There is provided in the wing section I3 of the unit Illa water-atomizing mechanism 1I having an inlet 12 connected both to the condensate receptacle 64 and to a source of water supply, 1ndicated in general by the reference character 13, and having an outlet 14 connectable selectively to the inner end of a conduit arranged in the duct I6 andpcommunicating with the external atmosphere, and to the lower end of a humiditying nozzle 16 extending through the top wall of the section I3 and communicating with the room space.

The mechanism 1I is of the conventional motor-driven -centrifugal type, and comprises a stationary cup-shaped water receptacle 11 having the inlet 12 formed therein and being supported by the bottom wall of the section I3, a wateratomizing unit 18 supported by the upper rim of the receptacle 11 and having a rotating Waterfeed tube 19 extending below the level of the Water in the receptacle 11, and a conical-shaped dome 80 also supported by the rim of the receptacle 11 and housing the upper part of the unit 18 and having the axial outlet 14.

The inlet 12 is connected to the condensate receptacle 64 and water supply means 13 by substantially horizontal extending pipes 8| and 82. The water supply means 13 is here shown as being of the conventional inverted water-bottle type, and comprises a cup-shaped water-receiving receptacle 83 supported by a bracket 84 from the bottom wall of the wing section I2, and a removable water-supply bottle 85 supported in inverted position by the rim of the receptacle 83.

It will thus be seen that when there is a supply of water in the bottle 85, or when there is sufllcient water in the condensate receptacle 64, such water will flow by gravity through the pipes 82 and 8| into the receptacle 11 of the mechal nism, and when the mechanism 1| is operated, this water will be vaporized and discharged upwardly'through the outlet 14. It may be observed at this point that during the summertime, when the cooling coil 56 is in operation, the water-supply bottle is not lled, and the water supplied to the receptacle 11 of the mechanism 1I is condensate collected in the receptacle 64 from the coil 56. In the Wintertime, when the cooling coil is not in operation, the water-supply bottle 85 is lled with water, and such water will how by gravity into the receptacle 11 in the manner aforementioned.

A ilexible hose 86 serves to connect selectively the outlet 14 of the mechanism 1| to the conduit 15 and to the humidifying nozzle 16. The lower end of the hose is fixed to the dome 80, and the upper end may loosely lit either the lower end of the nozzle 16 or the conduit 15. The connection of the upper end of the hose either to the nozzle or to the conduit may be quickly eilected by hand. In the summertime when the cooling coil is in operation, the upper end of the hose 86 is connected to the conduit 15, as indicated in dotted lines in Fig. 3. In the wintertime when humidity is required in the room, the upper end of the hose 86 is connected to the lower end of the nozzle 16, as indicated in full lines in Fig. 3.

It is to be noted that the particular construction and arrangement of a water-atomizing mechanism which has an inlet'connected to a condensate receptacle and to a water supply means, and which has an outlet selectively connected to the external atmosphere and to a humidifying nozzle, is not in itself a part of the present` invention, it having been disclosed and claimed in the copending application of Robert D. Lambert, Serial No. 118,461, led December 31, 1936. Insofar as the present invention is concerned, this mechanism and its connection to the condensate receptacle and to the water supf ply means, and its selective connection to the duct 15 and nozzle 16, may be considered as one of the elements which are controlled by our improved control system, in a manner which will appear more fully hereinafter.

It is also to be noted that the particular structure and arrangement of the central section and the wing sections lI2 and I3, and the location and structure of the heating coil, the cooling coil, the lter, the blower, and the condensate receptacle, do not form in themselves a part of the' present invention, as they are disclosed and claimed in our copending application Serial No. 118,462, led December 31, 1936. insofar4 as the present invention is concerned, the heating coil and cooling coil and the blower may be considered only as elements which are controlled by our improved system.

In accordance with the present invention, we provide a means for shutting oli' the water-atomizing mechanism 1I when the level of the condensate in the receptacle 64 falls below a predetermined low level, or when the water supply bottle is empty, and for preventing flow of refrigerant to the coil 56 when the condensate level exceeds a predetermined high level. This means comprises rst and second normally closed switches 81 and 88, and a iioat or level-responsive device 89 arranged in the receptacle 64 and operating to open the switch 88 when the water level in the receptacle 64 falls below a predetermined minimum, and operating to open the switch 81 when the water level in the condensate receptacle exceeds a predetermined high level. Between the high level position and the low level position, both switches 81 and 88 remain closed. The switches 81 and 88 are arranged in separate circuits, including respectively the mechanism 1| and the refrigerant valve 6|, as will later appear.

In order that the cooling coil 56 will operate success-fully in the summertime to cool the particular room in which the unit is located, and will not become overloaded due to the admission into the room of too large a quantity of warm outdoor air, We have provided a damper limit switch 98 which remains closed as long as the damper 24 is adjusted to a position Where it will not admit to the passage more than a predetermined maximum amount of outdoor air, but which will open and prevent flow of refrigerant to the coil 56 should the damper be moved to admit more outdoor air than the predetermined maximum amount.

'I'he damper limit switch 9D is here shown as comprising a conventional form of mercury switch arranged in the wing section I3 and pivotally mounted on the wall dividing such wing section from the central section I I. The switch.9ll is connected for operation by a link 9| and arm 9Ia to an extension 24h of the shaft 24a. The switch 90 is in a circuit with the electrically operated valve 6I, and when the damper is moved in a direction to admit more outside air and beyond a preselected point, the switch 9|) opens the circuit, as will later appear. The point where the switch 90 will open may b'e varied by any suitable means, such, for example, as by a set screw 90a which when tight securesy the switch to its supporting shaft 90b. l

On the return line 69 of the heating coil 65 is located a suitable contact thermostat 92 which remains closed as long as a heating fluid is present in the coil 65, and which operates when the flow of heating uid is cut'ol to open a circuit including the electrically operated mechanism 25 for the damper 24, so as to close the latter and prevent cold outside air entering the room, and also so as to prevent freezing of the water-filled elements of, the unit IIJ, as will appear more fully hereinafter. It is to be noted that, while we have elected to show and describe a contact thermostat 92, insofar as the broader aspects of our invention are concerned, the thermostat 92 may be of any type and may be placed at any point where it will be subject to the temperature of the heating coil 65.

In accordance withk the present invention, we

vhave provided an improved control system which controls the operation of the previously described elements so that proper temperature and moisture conditions may be maintained in the room space throughout all seasons of the year. Our system may be operated to maintain these conditions selectively by manual control and by automatic control in response to an adjustable room thermostat. The structure of the room thermostat is not indicated in the drawings, as it may be of any desired type; but the thermostat is indicated diagrammatically by the numeral 93 in Figs. 6 to 10 inclusive, as being one which closes a circuit upon a rise in room temperature beyond a preselected point, and which opens a circuit upon a fall in room temperature below a preselected point.

According to our invention, in the summertime, a refrigerant is supplied to the cooling coil 56 selectively by hand and in response to the room thermostat 93; condensate is continually removed by the mechanism 'II from the condensate receptacle 64 and discharged to the external atmosphere as long as there is Water in appreciable amounts in the receptacle; air from the room and from the outside is drawn into the passage 2l and discharged into the room to provide circulation and ventilation; and the damper 24 may be operated selectively by hand and automatically in response to the thermostat 93, to prevent flow of outdoor air into the passage 2| when refrigerant is not supplied to 'the coil, and to permit a predetermined flow of outdoor air into the passage 2I when refrigerant is supplied to the coil. In the wintertime, the hand valve III is opened; a heating uid from the pipe 68 is supplied to the coil 65; ventilation and air circulation are had in the room space; the damper 24 is opened and closed selectively by hand and automatically in response to the thermostat 93 so as to regulate the amount of relatively cold outdoor air admitted to the room and thereby control the temperature of the air in the room; and humidity is continuallysupplied to the room atmosphere by the mechanism 1I. In the spring and fall seasons, when heating or cooling of the room is not required, controllable amounts of 1 outdoor air and room air are constantly drawn into the passage 2I, filtered, and then introduced into the room to provide proper ventilation and air circulation.

As a part of our improved control system, We have provided a plurality of electrical circuits for affecting the operation of the various elements of the air conditioning unit previously described, so as to secure the healthful and comfortable conditions in the room space throughout all seasons of the year. These circuits are connected and disconnected to provide the various operations by means of a pair of three-position switches 94 and 95 mounted within a control box 96 suitably fixed to the under side of the top wall of the wing section I2. The switches 94 and 95 include operating knobs 94C and 91, respectively, which extend through the wing section top wall so as to be accessible for manipulation (see Figs. 1 and 11).

As viewed in Fig. 11, the left-hand switch 94 is designated the Master switch, and may be turned to three positions, namely, oif manual, and auto, the latter being an abbreviation of automatic The right-hand switch 95 is designated the Selector switch, and may also be turned to three positions, namely, air, humidify, and cool.' An intermediate control element is indicated by the reference numeral 98, and is designated Air volume. This element is a rheostat, and includes an operating knob 99, which is turned clockwise to increase the speed of the motor-driven blower 23, and counterclockwise to decrease its speed.

Referring now to Figs. 6 to 10 inclusive, it will be observed that we have indicated the two threeposition switches 94 and 95 as each being divided into upper and lower switch elements 94a, 94h, 95a, 95D. For the purpose of clarity, each of the switch elements is surrounded by dot-and-dash lines. The upper switch elements 94a. and 95a are shown diagrammatically as single-pole singlethrow switches. The lower element 94h of the switch 94 is shown as a single-pole double-throw switch, and the lower element 95D of the switch 95 is shown as a three-pole double-throw switch; but the latter may be considered as a single element mechanically, as the three blades of the switch are moved in unison by the knob 91.

In order to bring out more clearly the three positions of the upper and lower elements of each of the two-three-position switches 94 and 95, we have indicated diagrammatically in Fig. 12 the positions which the elements of each threeposition switch will assume for the corresponding positions 'of the control knobs 94C and 91. That is to say, position No. lf in Fig. 12 indicates both the position of elements 94a and 94b of switch 94 when the knob 94e is turned to the rst or "oif position, and also the position of the elements 95a and 95h of the switch 95 when the knob 91 is turned tothe first or `air position. Position No. 2, in Fig. 12, indicates both the position of the elements 94a and 94h of the switch 94 when the knob 94e is turned to the second or manual position, and also the position of the elements 95a and 95h of the switch 95 when the knob 91 is turned to the second or humidity position. Position No. 3 indicates both the position of the elements94a and 94h of the switch 94 when the knob 94e is turned to the third or auto position, and also the position of the elements 95a and 95h of the switch 95 when the knob 91 is turned to the third or cool position.

In Figs. 6 to 10 inclusive, the various elements if the air conditioning unit are indicated diagrammatically, and we have shown the numerous electrical connections/between these elements and the switches 94 and 95 which will provide the circuits used to control the operation of the air conditioning elements in the manner previously described. All circuits used in our control system are shown in each of these views, the difference being that each view indicates the circuits in use for a particular type of control during a particular season of the year; Aand in each instance the circuits used are indicated by heavy black lines and the circuits not in use are shown by relatively light lines. That is to say, in Fig. 6 we have indicated by heavy black lines the circuits in use and the positions of the switches 94 and 95 for controlling the operation of the air conditioning unit during the summertime, and which includes automatic control of the temperature of the room space in response to an adjustable room thermostat. Fig. '1 shows by heavy black lines the circuits in use during the summertime when the various operations of the unit are controlled manually. Fig. 8 shows by heavy black lines the circuits used for controlling the elements oi' the air conditioning unit during the wintertime, and for automatically regulating the temperature of the air in the room in response to a room thermostat. Fig. 9 shows by heavy black lines the circuits used for controlling manually the various operations required to condition properly the air in the room space during the detail the various electrical conductors and their connections with the switches and elements of the air conditioning unit which provide the several electrical control circuits used, and will then describe the circuits in use in each of Figs. 6, '1, 8,

9 and 10 which effect the various desired operations of the unit I0 previously described.

The various circuits may be operated from any suitable source of electrical supply, which may be either alternating or direct current. For convenience of description, the source may be considered as alternating current, and we have indicated this source as comprising a positive or supply conducton |00 and a negative or ground conductor I0|. The positive conductor |00 is connected to a junction point |02. One side of the switch element 94a of the switch 94 is connected to the junction point |02 by a short conductor |03. A conductor |04 connects the junction point |02 with a stationary contact |05 forming a part of the switch element h of the switch 95. The stationary contact |06 of the switch element 94a is connected to a junction point |01 by a short conductor |08, and the point |01 is connected by conductor |09 to one side of the singlepole double-throw switch element 94h. The point |01 is also connected with a junction point ||9 by ings of the motor forming a part of the motor-l driven blower 23. 'I'he motor or this blower may be of the conventional permanent split capacitor type. The point ||0 is also connected to a junction point ||3 by a short conductor ||4, and the point ||3 is connected to one side of the rheostat 98, and the other side of the rheostat 98 is connected by a conductor I5 with one side of the running windings of the motor of the motordriven blower 23. The other side of the starting and running windings of the motor is connected to the return or ground line I0| by means of a conductor H8. A conductor ||1 also connects the point ||3 with one side of the single-pole singlethrow switch element-95a of the switch 95. A conductor H8 connects the stationary contact ||9 of the switch element` 95a with the junction n point |20, and the latter is connected to a sta.- tionary contact |2I which is adapted to be contacted by the upper) movable blade |22 of the switch element 95h when the latter is in one position. 'Ihe point |20 is also connected to the middle blade l 23 of the element 95h by conductor |24. The upper movable blade |22 is permanently connected to one side of the atomizing mechanism 1| by a conductor |25. Ihe other side of the mechanism 1| is connected to one side of the normally closed switch 88 by conductor |28. and the other side of the switch 88 is connected to the return conductor |0| by conductor |21. The stationary contact |28 to be engaged by the intermediate blade |23 when'closed is connected by conductor |29 with one side of the room thermoable blade |34 of the switch element 95h by a conductor |35. Y v

The stationary contact |38 adapted to be engaged by the lower movable blade |34 is connected by a conductor |31 with one side of the mercury switch 90. The other side of the mercury switch is connected by a conductor |38 with one side of the electrically operated valve 6|., and the other side of the electrically operated valve is connected by a conductor |39 with one side of the normally closed switch 81, and the other side of the normally closed switch 81 is connected by a conductor |40 with the return conductor |0I.

One stationary contact |4| of the switch element 94h is connected by conductor |42 with one side of the contact thermostat 92, and the other side of the contact thermostat is connected to a junction point |43 in the conductor |29. The other stationary contact |44 of the switch element 94h is connected by a conductor |45 with the junction point 32.

Our complete control system includes seven electrical circuits under control of the switches 94 and 95 which operate the air conditioning elements previously described to provide comfortable conditions in theroom space throughout all seasons of the year.

As pointed out previously above, Fig. 6 of the drawings indicates by heavy black lines the electrical circuits used to operate the air conditioning unit during the summertime and to control automatically the temperature of the air in the room space. For this condition of operation, the

. knob 94c of the "Master switch" 94 is turned to the auto` position, as shown in Fig. 11, which corresponds to position No. 3 in Fig. 12, and the knob 91 of the Selector switch" 95 is turned to the cool position, which also corresponds to position No, 3 of Fig. 12. With the switches in these positions, all blades of elements 94a., 94h, 95a, and 95h, extend to the right as viewed in Figs. 6 and 12, and the blades will engage and close contacts |06, |4|, II9, |05, |28, and |36, respectively, Contacts |44 and |2| will be open.

With the switches in these positions, a rst circuit will be formed, extending from the posiltiveconductor |00, to the point |02, through the conductor |04,-b1ade |22, conductor |25, to the water-atomizing mechanism 1|, and from the latter through conductor |26, switch 88 and conductor |21 to the ground conductor ||J|. It will thus be seen that as long as the Selector switch 95 is turned to the cool" position. current will flow through this first circuit to operate the water-atomizing mechanism in response to the low-level switch 88; that is to say, the wateratomizing mechanism 1| will operate as long as there is a predetermined minimum kamount of water in the condensate receptacle 64. When the first circuit is in operation, the hose 86 is connected to the inner end of conduit 15, and the water-atomizing mechanism will operate to discharge the condensate from the receptacle 64 to the outdoors through the conduit 15.

With the switches in the positions indicated in Fig. 6, a second circuit will be formed, extending from point |02, through conductor |03, switch element 94a, conductor |08, conductor conductor ||2, conductor ||4, rheostat 98, and conductor 5, to the motor of the motor-driven blower, and from there through conductor ||6 to the ground conductor Thus, as long as the switch element 94a is closed, the motor-driven blower will operate to introduce intothe room, through the outlet |8, fresh air and/or room air, and the rheostat 98 may be regulated at will to vary the speed of the blower and thereby vary the amount of air introduced into the room in this manner.

With the switches 94 and 95 in the positions indicated in Fig. 6, a third circuit will be formed through conductor |03, switch element 04a., conductor |08, conductor conductor ||4, conductor ||1, switch elementI 95a., conductor ||8, conductor |24, blade |23, conductor |29, to the room thermostat 93, and from there through conductor |30 to point |3|. At point |3I, the circuit will divide into two branch parts connected in parallel, the first branch part extending through heat motor 5| to ground conductor |0|, and the second branchpart extending through conductor |33, 4to point |32; and from there through conductor |35, blade |34, and conductor |31, to damper-limitl switch 90; and from there through conductor |38 to selectively operated valve 6|; and from there by conductor |39, to switch 81; and from there through conductor |40 to the ground conductor |0|. Thus, with the switches in position to provide this third circuit, the damper 24 and the electrically operated valve 6| will be opened andclosed together in response to the room thermostat 93. Should the damper 24 be opened manually beyond the preselected maximum position previously described, the switch 90 will open and break the circuit through the valve 6| and thereby prevent refrigerant from flowing through the coil 56. The opening of the damper beyond the preselected maximum position would likely overload the coil 56 and the refrigerant supply mechanism, due to the introduction of an excess of warm outside air into the unit. Also, if the condensate in the receptacle 64 should exceed a predetermined high level, the switch 81 will open this third circuit and close the valve 6| and prevent iurther cooling until thek water-atomizing mechanism 1| can remove the excess amount of condensate from the receptacle 64. This latter arrangementwill prevent flooding of the unit on very hot, humid days. When the room thermostat 93 is satised, the damper 24 is closed along with the valve 6 I, so as to aid in holding the comfortable temperature in the room, and prevent the introduction of air from the outside having a relatively high humidity.

In Fig. 7 of the drawings, the heavy black lines indicate the control circuits in use during the summertime when the temperature in the room is controlled manually. Under these conditions, the Master switch" 94 will be in the manual" position as viewed in Fig. 11, which corresponds to position No. 2v shown in Fig. 12, and the Selector switch 95 will be in the cool position, or position No. 3," shown in Fig. 12. 'Ihe blade of element 94a will extend to the right, and the blade of element 9417 to the left. All blades 0f elements 95a and 95h will 'extend to the right as before. With the switches 94 and 95 in these positions, the blades of `the switch elements will close contacts |06, |44, ||9, |05, |28 and'l36, respectively. Contacts |4| and |2| will be open.

In Fig. '1, the first circuit described above in connection with Fig. 6 will be closed. As stated, this circuit does not include Master switch 94, but extends directly from the conductor |00 to the Selector switch 95 and then through the wateratomizing mechanism 1| andlow-level switch 88 to the ground |0|.

The second circuit described above, which is through the switch element 94a and rheostat 98 and. motor-driven blower 28 to the ground, will also be closed.

With the switches 94 and 95 in the positions indicated in Fig. 7, a fourth circuit will be established, extending through the switch elements 94a and 94h, contact |44, conductor |45, to the point |32; and will divide at point |32 into two branch parallel circuits, one branch flowing through conductor |33 to point |3|, heat motor 5|, and from there to the ground conductor |0|, and the other branch flowing through the conductor |35, blade |34, conductor |31, damper-limit switch 90, conductor |38, valve 6|, conductor |39, high-level switch 81, and conductor |40, to the ground conductor |0|.

The third circuit, which includes the thermostat 93 described above, will still be connected as it was before, but will not have any eiect on the operation, as thn fourth circuit shunts out the thermostat 93 and connects the source of energy directly withthe two branches, including respectively the damper 24 and the valve 6|. In the fourth circuit, the solenoid valve will also close if the damper 24 is opened beyond the maximum preselected point, or if the amount of condensate Vin the receptacle 64 exceeds the predetermined high level. In the circuits in use in Fig. .'7, the condensate will be removed from the receptacle 64 as long as there is suflicient water therein, and

stat 93. Under these operating conditions, the

Master switch 94 will be turned to the auto position shown in Fig. l1, which corresponds to position No. 3 shown in Fig. 12,` and the Selector switch 95 will be in the "humidify position, corresponding to position No. 2 of Fig. 12. With the switches in these positions, the blades of elements 94a and 94h will extend to the right, the blades of element 95a to the right, and the blades of 95b to the left. Contacts- |06, |4|, H9, and 2| will be closed, and contacts |44, |05, |28, and |36 will be open. The second circuit described above in connection with Fig. 6 Awill be in use; that is to say, current will flow through the element 94a of the Master switch 94, through conductor |08, conductor conductor ||2, conductor ||4, rheostat 98, and conductor ||5 to the motor-driven blower 23, and from there through conductor ||6 to the ground conductor |0|. As before, the speed of the blower 23 will be regulated by hand-adjustment of the rheostat 98.

With the switches in these positions,l a fifth circuit will be established, which will also include the switch element 94a, and will ow through conductors |08, ||4, and conductor ||1 to switch element 95a; and from there through conductor ||8, point |20, to contact |2| from there through blade |22 and conductor |25, to the water-atomizing mechanism 1|; and from there through conductor |26, low-level switch 88, conductor |21, to the ground conductor |0|. In the wintertime, the hose 86 is connected to the humidifying nozzle 16, and water from the Water-supply means 13 will be atomized by the mechanism 1| and will be introduced into the room in the form of a fine mist through the nozzle 16. Should the water-supply bottle become empty, the switch 81 will open and prevent further operation of the mechanism 1|. This latter is due to the fact that the pipes 8| and 82 are connected to one another, and water from the supply means 13 will flow by gravity into the receptacle 64 as well as into the receptacle 11 of the water-atomizing mechanism 1|.

With the switches 94 and 95 in the positions indicated in Fig. 8, a sixth circuit will be established, which also includes the element 94a of the Master switch 94, and includes conductor |08, conductor |09, switch element 9417, contact |4I, conductor |42, contact thermostat 92, conductor |29, room thermostat 93, conductor |30 and heating element 5|. Thus, the damper 24 is opened` and closed in response to the room thermostat 93, the thermostat 92 being closed as long as there is heat in the coil 65. According to this operation, the room temperature will be regulated by the amount of relatively cold outdoor air introduced into the unit through the opening |5.

It is to be noted at this point that in Fig. "6 the switch element a is in, the position to close this sixth circuit just described, but, due to the fact that there is no heat in the coil in the summertime, the contact thermostat 92 is always open in Fig. 6 and the sixth circuit is not established.

In Fig. 9 of the drawings, the switches 94 and 95 are shown in position to supply comfortable conditions in the room space duringthewintertime, and the damper 24 is operated manually from the switch 94b to regulate the room tempera ture. In order to secure these conditions. the Master switch 94 is in the manual position oi Fig. 11, corresponding to position No. 2" of Fig. 12, and the Selector switch 95 is in the humidify" position, corresponding to position No. 2" in Fig. l2.

With the switches in these positions, the blades of switch elements 94a and 95a extend to the right, the blades of switch elements 94h and 95a exend to the left, contacts |06, |44, ||9 and |2| are closed, and'contacts |4|, |05, |28 and |36 are open. The second circuit described above in connection with Fig. 6 is closed, and, as before, the amount of room air and/or fresh air introduced into the room is controlled by the rheostat 98. Also, the fth circuit, described above in connection with Fig. 8, is in operation. This circuit'is through the switch element 94a, conductor |08, conductor conductor ||4, conductor ||1, switch element 95a, conductor H8, blade |22, conductor |25, to the water atomizer 1|, and from there through conductor |26, lowlevel switch 88, conductor |21, to the ground conductor |0|. As was the case in Fig. 7, humidity will be supplied to the room space as long as there is suflicient water in the water-supply means 13.

In Fig. 9, a seventh circuit is established by the switches in the positions indicated. This circuit is through the switch element 94a, conductor |08, conductor |09, contact point |44, conductor |45, to the heating element 5| of the damper-operating mechanism, and from there `to the ground conductor |0|. Thus, the opening and closing of the damper 24 is under direct control of the Master switch 94. It will be noted that this seventh circuit is practically the same as the fourth circuit described above, only in the seventh circuit the blade |34 is open, due to the position of the switch element 95b of the Selector switch 95, and for this reason no current can flow through this branch to the valve 6|.

In Fig. 10 of the drawings, we have shown by heavy black lines the circuits used to 'furnish clean outdoor air into the room space during the spring and fall, when no heating, cooling, humidifying or dehumidifying is required. Under these conditions, switch 94 is shown in the "manual position, or the position No. 2 in Fig. 12, and switch 95 is shown in the air position, or the position No. 1 in Fig. 12. With the switches in this position, only contacts |06 and |44 are closed. Nocurrent can flow through the switch 95, as all of the switchblades are to the left as viewed in Fig. 1. With the switches in this position, the second circuit described above, which is through the rheostat and motor-driven blower, is closed; and the seventh circuit, described in connection with Fig. 9, is also closed, the latter extending through the switch element 94h, contact |44, conductor |45, conductor |33, to the heat motor 5|, and from there to the ground 0|. Thus, desired proportions of fresh and room air may be introduced into the room, and the rate of air ow may be regulated by the rheostat 98.

From the above, it will be apparent that any desired condition can be obtained in the room by the simple manipulation of the Master switch 94 and the Selector switch 95, and that in the summertime and in the Wintertime the room temperature may be controlled selectively by hand and automatically by a room thermostat. This is effected in the summertime by changing the Master switch" 94 from manual to auto, and vice versa, and leaving the Selector switch 95 on cool. In the wintertime, when there is heat in the coil 65, the room temperature is controlled selectively by hand and automatically in response to a room thermostat, and this is accomplished -by changing the Master switch 94 from the auto position to the manual position, and vice versa, leaving the Selector switch 95 either at humidify, if humidity is desired, or at air,- if humidity is not desired. In the spring and fall, when the heating fluid is not supplied to the coil 65 and the cooling fluid is notsupplied to the coil 56, the unit I0 may be operated to admit desired amounts of fresh air and to circulate the air in the room by positioning the Master switch 94 at manual and the Selector switch 95 at ain It will also be noted that under all conditions of operation, the speed of the motor-driven blower is under control of the rheostat 98.

What we claim and desire to secure by Letters Patent of the United States is:

1. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing deningav passage connecting said inlets with said outlet; a damper for controlling the ow of air through said fresh air inlet; a cooling coil in said passage; a heating coil in said passage; motor-driven blower means for effecting flow of air through said passage; a receptacle arranged to receive condensate from said cooling coil; a motor-driven water-atomizing mechanism having an inlet connected to said receptacle and an outlet connectable selectively to said room space and .to the outside atmosphere; Water supply means connectable to said mechanism inlet; and control mechanism for operating the heatingcoil, cooling coil, damper, and water-atomizing mechanism, so that during the heating season a heating uid is supplied to the heating coil, moisture is supplied to the room space by said atomizing mechanism, and

the damper is operated selectively by hand and is discharged to the outside atmosphere bysaid atomizing mechanism.

2. An air conditioning unit for rooms, compris-'- ing a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing defining a passage connecting said inlets with said outlet; a damper for controlling the How of air through said fresh air inlet; a cooling coil in said passage; a hea-ting coil in said passage; motor-driven iblower means for eiecting W of air through said passage; a receptacle arranged to receive condensate from said cooling coil; a motor-driven water-atornizing mechanism having an inlet connected to said receptacle and an outlet connectable selectively to said room spaceand to the outside atmosphere; water supply means connectable to said mechanism inlet; and control mechanism for operating the heating coil, cooling coil, damper, and water-atomizing mechanism, so that, during the heating season, -a heating uid is supplied to the heating coil, moisture is supplied to the room space by said atomizing mechanism, and the damper is selectively operated by hand and in response to room temperature to control the amount of fresh air entering the room, and sothat, during the cooling season, a refrigerant fluid is supplied to the cooling coil selectively .by hand and in response to the temperature of the room, the damper is operated selectively by hand and in response to the room thermostat for controlling theow of fresh air into the room, and condensate collected in said receptacle is discharged to the outside atmosphere by said atomizing mechanism.

3. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculatedair inlet and a room yair outlet; means in said casing defining a passage connecting said' inlets With said outlet; a damper for controlling the flow of air through said fresh air inlet; a cooling coil in said passage; a heating coil in said passage; motor-driven blower means for effcc-ting flow of air through said passage; a receptacle arranged to receive condensate from said cooling coil; a motor-driven water-atomizing mechanism having an inlet connected to said receptacle and an outlet connectable selectively to said room space and to the outside atmosphere; water supply means connectable to said mechanism inlet; and control mechanism for effecting operation of said damper, heating coil, cooling coil, blower, and atomizing mechanism so that proper temperature and humidity conditions may be maintained in the room throughout all seasons of the year; said control mechanism including devices for .controlling the operation of the blower, devices controlling the operation of said cooling coil and said damper selectively by hand and in response to room temperature conditions, devices for 4controlling the operation of said heating coil and devices for controlling said damper so as to provide a comfortable room temper-ature selectively by manual control and ,by thermostatic control, and devices for selectively operating said atomizing mechanism to supply humidity to the room space from said water supply means and for discharging condensate from said receptacle to the outside atmosphere.

4. An air conditioning unit for rooms, com'-A prising a casing having a fresh air inlet, a recirc'ulated air inlet and a room air outlet; means sot Iin said casing defining a passage connecting said inlets to said outlet; an electrically operated 'dam-per for controlling the flow of air through said fresh air inlet; a cooling coil in said passages; a heating coil in said passage and including means for controlling the flow of the heating uid thereto; a motor-driven blower for effecting flow of air through said passage; a receptacle arranged to receive condensate from said cooling Icoil; a motor-driven water-atomizing mechanism having an inlet connected to said receptacle, and an outlet connectable selectively to the outside atmosphere and to said room space; water supply means connectable to said receptacle; and control mechanism for eifecting the operation of VYsaid elements so as to provide proper temperature and humidity conditions in the room space throughout all seasons of the year; said control mechanism comprising an adjustable room thermostat operable -to close uponl a rising temperature and to open upon a falling temperature, an electrically operated device for controlling the flow of refrigerant to said cooling coil, asource of electrical energy, 'circuit means connectable to said source and operable to connect said electrically operated device selectively for manual control and for control by said thermostat, circuit means 'connectable to said source and selectively connecting said electrically operated damper for hand operation and for operation by said thermostat, a normally closed switch, means responsive to the liquid level -in said receptacle for opening said switch when the level therein reaches a predetermined low point, and electrical circuit means connectable to said source for operating said water-atomizing mechanism and including in series therein said normally closed switch.

5. An air conditioning unit for room spaces, comprising a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said 'casing defining a passage connect- .ing said inlets with said outlet; an electrically operated damper mechanism providing for flow of air through said fresh air inlet when energized and preventing iiow when deenergized, a cooling coil in said.' passage; an electrically operated device providing for ow of a refrigerant to said coil when energized and preventing ow'when deenergized; a heating coil in said passage; controllalble means for supplying a heating fluid to said coil; an electrically operated. blower for effectlng flow of air through said passage; a receptacle arranged to receive condensate `from said cooling coil; rst and second normally closed switches; means for opening said iirst switch at a predetermined low water level in said receptacle, and for opening said second switch at a predetermined lhigh level; an electrically operated water-atomizing mechanism including an inlet connected to said receptacle andi an outlet selectively 'connectable to said room space and to the outside atmosphere; water supply means connectable to said receptacle; an adjustable thermostat operable to close upon a rising room temperature and to open upon `a falling temperature; a source. of electrical energy; a iirst electrical circuit connectable to said source and including in series said atomizing mechanism and Said first switch; a master switch; a second electrical circuit connectable to said' source and including in series said master switch and said blower; a third electrical circuit connectable to said source and comprising amain part including inseries the master switch and room thermostat and two branch parts connected in parallel, with one of the branches including in series said device and saidI second switch, and the other branch including said damper; a fourth circuit connectable to said source and comprising a main part including said master switch, and two branch parts connected in parallel, with one of the branch parts including in series said device and said second switch, and the other branch part including said damper; a flfth circuit connectable to said source and including in series said master switch', said atomizing mechanism and said rst switch; a sixth circuit connectable to said source and including in series said master switch, said thermostat and said damper; and a seventh cir-l cuit connectable to said source and including in series said master switch and said damper.

6. In air conditioning apparatus for use in room spaces, the combination of an electrically driven air circulating device; a cooling coil for reducing the temperature of and condensing moisture from the air circulated by said device; a receptacle for collecting condensate from said coil; an electrically operated means for removing conand including in series a hand-operated switch,

the electrically operated condensate removal means, and said normally closed switch.

7. In air conditioning apparatus for use in room spaces, the combination of an electrically driven air circulating device; a cooling coil for reducing the temperature of and condensing moisture from the air circulated by the device; an electrically operated device providing for flow of refrigerant to said cooling coil when energized, and preventing ow when deenergized; a receptacle for collecting condensate from said coil; an electrically operated means for removing condensate from said receptacle; a normally closed switch; means responsive to a predetermined low level of condensate in said receptacle for opening said switch; a first main control circuit including in series a hand-controlled switch and two branch circuits arranged in parallel, one of said branch circuits being connected to operate said air circulating device, and the other of said branch circuits 'including therein said refrigerant control device; and a second main control circuit separate from said first main control circuit, and including therein in series the electrically operated condensate removal means and said normally closed switch.

8. In air conditioning apparatus for use in room spaces, the combination of means defining a iiow path for air; means providing for the flow of air through said path; a cooling coil arranged across said path for reducing the temperature of and condensing moisture from the air ilowing therethrough; an electrically operated device providing for flow of refrigerant to said coil when energized and preventing flow whendeenergized; a receptacle for collecting condensate from said coil; an electrically operated means -for removing condensate from said receptacle; ilrst and second normally closed switches; means responsive to a predetermined low level of condensate in said receptacle for opening said first switch, and responsive to a predetermined high level for opening said second switch; a control circuit including in series said condensate removal means and said first switch; and a second control circuit including in series said device and said second switch.

9. In air conditioning apparatus for use in room spaces, the combination of an electrically driven air circulating device; a cooling coil for reducing the temperature of and condensing moisture from the air circulated by the device; an electrically operated device providing for ilow of refrigerant to said cooling coil when energized, and preventing flow when deenergized; a receptacle for collecting condensate from said coil; an electrically operated means for removing condensate from said receptacle; a normally closed switch; means responsive to a predetermined low level of condensate in said receptacle for opening said switch; a control circuit including in series a hand-controlled switch and two branch circuits connected in parallel, with one of said branch circuits being connected to operate said air circulating device, and the other of said branch circuits 'including therein in series said refrigerant control device and a thermostat reries the electrically operated condensate removal means and said noramlly closed switch.

10. In air conditioning apparatus for use in room spaces, the combination of an electrically driven air circulating device; a cooling coil for reducing the temperature of and condensing moisture from the air circulated by the device; an electrically operated device providing for flow of refrigerant to said cooling coil when energized, and preventing flow when deenergized; a receptacle for collecting condensate from said coil; an electrically operated means for removing condensate from said receptacle; a normally closed switch; means responsive to a predetermined low level of condensate in said receptacle for opening said switch; a control circuit including in series a hand-operated switch and three branch circuits connected in parallel, with one of said branch circuits being connected to operate said air circulating device, the second of said branch circuits including in series a thermostat responsive to variations in room temperature and said electrically operated device, and the third of said branch circuits including in series a handoperated switch and said electrically operated device, and operable when said last-named switch is closed to shunt out said thermostat and second branch circuit; and a second control circuit separate from said first control circuit and including therein in series the electrically operated condensate removal means and said normally closed switch.

11. An air conditioning unit for rooms, comprising a casing having a fresh air inlet,` a recirculated air inlet and a room air outlet; means in said casing defining a passage connecting both of said inlets with said outlet; an electrically driven air circulating device providing for flow of air through said passage; an electrically operated damper providing for flow of. air through said fresh air inlet when energized and preventing iiow when deenergized; a cooling coil arranged within said passage; a receptacle for collecting condensate from said coil; an electrically operated means for removing condensate from said receptacle; a normally closed switch; means responsive to a predetermined low level of condensate in said receptacle for opening said switch; a first main control circuit including in series a hand-operated switch and two branch circuits connected in parallel, with one of said branch circuits including the electrically Vdriven air circulating device, and the other of said branch circuits including in series a hand-operated switch and said electrically operated damper; and a second main control circuit arranged in parallel with the first main circuit and includ-4 ing in series a hand-operated switch, the electrically operated condensate removal means, and said normally closed switch.

12. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing dening a passage connecting both 0f said' inlets with said outlet; an electrically driven air circulating device providing for iicw of air through said passage; an electrically operated damper providing for flow of air through said fresh air inlet when energized and preventing flow when deenergized; a cooling coil arranged within said passage; a receptacle for collectiva condensate from said cgil; an electricauy operated means for removing condensate from said receptacle; a normally closed switch; means responsive to a predetermined low level in said condensate receptacle for opening said switch; a rst main control circuit including in series a hand-operated switch and two branch circuits connected in parallel, with one of said branch circuits including the electrically driven air circulating device, and the other of. said branch circuits including in series a hand-operated switch, said electrically operated damper, and an adjustable room thermostat operable to close said circuit upon a rising room temperature and to open said circuit upon a falling temperature; and a second main control circuit connected in parallel with said first main circuit and including in series a hand-operated switch, the electrically operated condensate removal means, and said normally closed switch.

13. An air conditioning unit for rooms, comprising a casing having a. fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing defining a passage connecting both of said inlets with said outlet; an electrically driven air circulating device providing for flow of air through said passage; an electrically operated damper providing for flow of. air through said fresh air inlet when energized and preventing flow when deenergized; a cooling coil arranged within said passage; an electrically operated device providing for flow of refrigerant to said coil when energized and preventing iiow when deenergized;` a receptacle for collecting condensate from said coil; an electrically operated means for removing condensate from said receptacle; a normally closed switch; means responsive to a predetermined low level in said condensate receptacle for opening said switch; a first main control circuit including in series a hand-operated switch and two branch circuits connected in parallel, with one of said branch circuits including the electrically .driven air circulating device, and the other of said branch circuits including a hand-operated switch, said electrically operated device and said electrically operated damper; and a second main control circuit connected in parallel with said first main circuit and including in series a hand-operated switch. said condensate removal means, and said normally closed switch.

14. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing defining a passage connecting both of said inlets with said outlet; an electrically driven air circulating device providing for flow of, air through said passage; an electrically operated damper providing for flow of air through said fresh air inlet when energized and preventing flow when deenergized; a cooling coil arranged within said passage; an electrically operated device providing for flow of refrigerant to said coil when energized and preventing flow when deenergized; a receptacle for collecting condensate from said coil; an electrically operated means for removing condensate from said receptacle; a normally closed switch; means responsive to a predetermined low level of condensate in said receptacle for opening said switch; a i'lrst main control circuit including in series a hand-operated switch and two branch circuits connected in parallel, with one of said branch circuits including the electrically driven air circulating device, and the second branch circuit including in series a main part and two branch parts connected in parallel, the main part of said second branch including a hand-operated switch, one of said branch parts including said electrically operated damper, and the other of. said branch parts including a hand-operated switch and said electrically operated device; and a second main control circuit connected in parallel with the first main circuit and including in series Aa hand-operated switch, the electrically operated condensate removal means, and said normally closed switch.

15. An air conditioning unit for rooms, comprisinga casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing defining a passage connecting both of said inlets with said outlet; an electrically driven air circulating device providing for ow of air through said passage; an electrically operated damper providing' for flow of air through said fresh air inlet when energized, and preventing flow when deenergized, a first normally closed switch; means actuated by the opening of said damper beyond a preselected position for opening said first normally closedswitch; a cooling coil arranged within said passage; an electrically operated device'providing for flow of refrigerant to said coil when energized, and preventing flow when deenergized; a receptacle for collecting condensate from said coil; an electrically operated means for removing condensate from said receptacle; a second normally closed switch; means responsive to a predetermined low level in said condensate receptacle for opening said second normally closed switch; a first main con,- trol circuit including in series a hand-operated switch and two branch circuits connected in parallel, with one of said branch circuits including the electrically .driven air circulating device, and

-the other of said branch circuits including in series a main part and two branch parts connected in parallel, the main part of said second branch circuit including a hand-operated switch,

one of said branch parts including said electrically operated .dampen and the other of said branch parts including in series a hand-operated switch, said rst normally closed switch, and said electrically operated device; and a second main control circuit connected in parallel with the first main circuit and including in series a handoperated'switch, the electrically operated condensate removal means, and said second normally closed switch.-

16. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculated air inlet and a room .air outlet; means in said casing defining a passage connecting both of said inlets with said outlet; means providing for the iiow of air through said passage and into said room through said outlet; an electrically operated damper providing for flow of air through said fresh air inlet when energized, and preventing flow when de energized; a cooling coil arranged within said passage; an electrically operated device providing for fiow of refrigerant to said coil when energized, and preventing flow main control circuit includingin series a main part and two branch parts' in parallel; the lastnamed main part including a. second hand-operated switch operable when closed to shunt out said first main control circuit 'and said thermostat; one of said last-named branch parts including in series said first hand-operated switch and said electrically controlled device, and the other of said last-named branch parts including said electrically operated damper.

17. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing defining a passage connecting both of` said inlets with said outlet; means providing for the fiow ofl air through said passage; a damper for controlling the flow of air through said fresh airrlnleta cooling coil arranged within said passage; valve mechanism for controlling the flow of refrigerant to said cooling coil; and control mechanismA `for operating said valve mechanism and including means actuated by the opening of said damper beyond a preselected position for closing said valve mechanism and pr'eventing flow of refrigerant to said coil.

18. An air conditioning unit for rooms, comprising' a casing having a fresh air inlet, a re- `said damper beyond a preselectedl positionv for opening said normally closed switch; a cooling coil arranged within said passage; an electrically' operated valve providing for flow of refrigerant to said coil when energized, and'preventing flow when deenergized; and an electrical control circuit including in series said normally closed switch land said electrically operated valve.

19. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means ,in said casing defining a passage connecting both of said inlets with said outlet; means providing for the fiow of air through said passage; an electrically operated damper providing for flow of air through said fresh air inlet when energized, and preventing flow when deenergized; a normally closed switch; means actuated by the opening of said dam-per beyond a preselected position for opening said normally closed switch; a cooling coil arranged within said passage; an electrically operated valve 'providing for flow of refrigerant to said coil when energized 'and preventing flow when deenergized; and electrical circuit means operable selectively by hand and in response to room temperature conditions for actuating said electrically controlled valve; said circuit -means including in series said normally closed switch and said valve.

20. An air conditioning unit for rooms, comprising a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means in said casing defining a passage connecting both of said inlets with said outlet; means providing for the positive ow of air through said passage and into said room threaghsaid outlet; a damper for controlling the flow of air through said fresh air inlet; a cooling coil arranged within said passage; a receptacle for collecting condensate from said coil; valve mechanism for controlling the flow of refrigerant to said coil; and control mechanism for operating said damper andsaid valve mechanism so that the damper is opened and fresh air is permitted to iiow into the passage when refrigerant is supplied to said coil, and the damper is closed when said valve mechanism is operated to preventl the iiow of refrigerant to saidcoil; said control mechaism'including means responsive to a predetermined maximum amount 'of condensate in said receptacle forl closing said valve mechanism.

21. In air conditioning apparatus for use in rooms, the combination of means dening a ow path for air; means providing for the positive owof air through said path; a cooling coil arranged across said path for reducing the temperature of `and condensing moisture from the air flowing therethrough; a receptacle for collecting condensate from said coil; valve mechanism f for controlling the ow of refrigerant to said coil; and means responsive to a predetermined maximum amount of condensate in said receptacle for closing said valve and preventing the iiow of refrigerant to said coil.

22. In air conditioning apparatus for use in room spaces, the combination of a casing having spaced inlet and outlet openings; means in said casing defining a` passage connecting said inlet and outlet openings; a motor-driven -blower for effecting flow of air through said passage; a cooling coil in said passage; valve mechanism for controlling the floW- of a refrigerant fluid to said cooling'coil; a receptacle arranged'to receive condensate from said coil; a motor-driven wateratomizlng mechanism having an inlet connected to said receptacle and having an outlet connectable selectively to the outside atmosphere and to said control mechanism comprising rst and second electrical control circuits connected in parallel; said first circuit including in series a main part and two branch parts connected in parallel; the main part including a master hand-operated switch, one. of said branch`parts `including said blower and the other of said .branch parts including said water-atomizing mechanism; said second circuit including in seriesa hand switch and said motor-driven water-atomizing mechanism, the operation of said second circuit being such that when said last-named hand switch is closed, the water-atomlzing mechanism is operated -through said second circuit, even though said master switch may be open.

23. In air conditioning apparatus for use in room spaces, the combination of a casing having spaced inlet and outlet openings; means in said casing defining a passage connecting said inlet and outlet openings; a motor-driven blower for effecting flow of air through said passage; a cooling coil in said passage; valve mechanism for controlling the flow of a refrigerant fluid to said cooling coil; a receptacle arranged to receive condensate from said coil; a normally closed atomizing mechanism isi-operated to atomize,l

`water from said supply means and discharge such atomized water into the room when said valve mechanism is closed and additional humidity is desired in the room; said control mechanism comprising iirst and second electrical controlr circuits connected in parallel; .said first circuitv including in series a main part and two branch parts connected in parallel, the main part including a master hand-operated switch, one of said branch parts including said blower means and the other of said branch parts including in series said water-atomizing mechanism and said normally closed switch; said second circuit including in series ahand switch, said motor-driven water-atomizing mechanism and said normally closed switch, the operation of said second circuit being such that when said last-named hand switch is closed, the water-atomizing mechanism is operated solely through said second circuit.

24. In air conditioning apparatus for use in room spaces, the combination of a casing having a fresh air inlet opening, a recirculated air inlet opening, and a room air outlet opening; means in said casing defining a passage connecting said inlet and outlet openings; motor-driven blower means for effecting flow of air through said passage and into said room through said outlet opening; an electrically operated damper for controlling the flow of fresh air through said fresh air inlet opening; an adjustable thermostat responsive to temperature variations in saidroom spaces; and electrical control means for operating said blower and said damper, and including a source of electrical energy, and first, second and third electrical circuits connected in parallel to said source; one of said circuits including said blower, the second of said circuits including in series said thermostat and said electrically operated damper, and the third of said circuits including said damper; said control means also including switching means for selectivity connecting said second and third circuits to said source.

25. In air conditioning apparatus for use inb room spaces, the combination of a casing having a fresh air inlet opening, a recirculated air inlet opening, and a room air outlet opening; means in said casing dening a passage connecting said inlet and outlet openings; a motor-driven blower for effecting flow of air through said passage and into the room through said outlet opening; an electrically operated damper for controlling flow through said fresh air inlet; Aan electrically operated water-atomizing mechanism; an adjustable thermostat responsive to changes in room temperature; electrical control means for effecting the operation of said blower, said-wateratomizing mechanism and said damper, and including a source of electrical energy and first, second, third and fourth circuits connected in parallel to said source; the first of said circuits I including said blower, the second of said circuits including in series a hand-operated switch and said water-atomizing mechanism, the third of said circuits including in series said thermostat and said damper, andthe fourth of said circuits including said damper; said control means also .including switching means for selectively connecting said third and fourth circuits to said source.

26. In air conditioning apparatus for use in room spaces, the combination of a casing having a fresh air inlet opening, a recirculated air inlet opening, and a room air outlet opening; means in said casing defining a passage connecting said inlet and outlet openings; electrically operated blower means for eiecting the ilow of air through said passage and into said room through said outlet opening; a heating coil in said passage; an electrically operated damper controlling the ilow of air into said passage through said fresh air inlet opening; a rst adjustable thermostat responsive to temperature changes in said room; a second thermostat responsive to temperature changes in said heating coil; and electrical means for controlling the operation of said blower and said damper, and including a source of electrical energy and first, second and third electrical control circuits connected in parallel to said source; the first of saidcircuits including said blower, the second of said circuits including in series said first and second thermostats and said electrically operated damper, and the third of said circuits including said damper; said electrical means also including a switching means for selectively connecting said second and third circuits to said source.

27. In air conditioning apparatus for use in room spaces, the combination of a casing having a fresh air inlet opening, a recirculated air inlet opening, and a room air outlet opening; means in said casing defining a passage connecting said inlet and outlet openings; electrically operated blower means for effecting the flow of air through said passage and into said room through said outlet opening; a heating coil in said passage; an electrically operated damper controlling the flow of air into said passage through said fresh air inlet opening; thermostatic means responsive to temperature changes in air flowing from said heating coil; and electrical means for controlling the operation of said blower, and including -a source of electrical energy and first, second and third electrical control circuits connected in parallel to said so'urce; the first of said circuits including said blower means, the second of said circuits including in series said thermostatic means and electrically operated damper, and the third of said circuits including said damper; said electrical means also including a switching means for selectively connecting said second and third circuits to said source.

28. In air conditioningapparatus for use in room spaces, the combination of a casing having a fresh air inlet, a recirculated air inlet and aA room air outlet; means in said casing defining a passage connecting both of said inlets with said energized; a heating coil in said passage; and control mechanism for regulating the temperature of the air flowing through said passage and for controlling the supply of fresh air, so that during the colder months of the year heat is supplied to the heating coil and the damper is operated to control the iiow of fresh air into said passage, and so that during the hotter months of the year, the heating coil is shut off and a refrigerant fluid is supplied to the cooling coil and parallel, said main part including a hand-operated switch, one of said branch parts including said electrically'operated damper, and the other of said branch parts including in series a hand switch and said electrically operated device; said control mechanism also including means operated separately from said electrical circuit for controlling the iiow of heating iluid to said heating coil.

29. In air conditioning apparatus for use in room spaces, the combination of a casing having a fresh air inlet, a recirculated air inlet and a room air outlet; means providing for the positive iiow of air through said passage and into said room through said outlet; an electrically operated damper for controlling the flow of fresh air f` l into said passage through said fresh air inlet; a heating coil arranged across said passage for raising the temperature ofthe air owing therethrough; valve mechanism for controlling the flow of heating fluid to said coil; a first thermostat responsive to the temperature of said coil; a second thermostat responsive to changes in room temperature; a source of electrical energy; a first electrical circuit including in series said second thermostat and said electrically operated damper; a second electrical circuit including in series said first thermostat, said second thermostat, and said electrically operated damper; and switching means for selectively connecting said nrst and second circuits to said source.

30. In air conditioning apparatus for use in room spaces, the combination oi a casing having a fresh air inlet. a recirculated air inlet, and a room air outlet; means providing for the positive flow of air through said passage and into said room through said outlet; an electrically operated damper for controlling the flow of fresh air into said passage through said fresh air inlet; a heating coil arranged across said passage for raising the temperature of the air flowing therethrough; valve mechanism for controlling the ow of heating fluid to said coil; thermostatic means responsive to the temperature of the air flowing from said coil; a source of electrical energy; a first electrical circuit including in series said thermostatic meansand said elec-l trically operated damper a second electrical circuit including said electrically operated damper;

and switching means for selectively connecting` said rst and second circuits to said source.

31. In air conditioning apparatus for use in room spaces, the combination of a casing having a fresh air inlet, a recirculated air inlet, and a Y room air outlet; means providing for the positive flow of air through said passage and into said room through said outlet; an electrically operated damper operable to permit flow of fresh air through said fresh air inlet when energized, and to prevent flow when deenergized; a heating coll arranged across said passage for raising the 14 2,212,239 temperature of the air flowing therethrough; circuit; a source of electrical energy; and an mechanism arranged within said casing and opelectrical controi circuit connected to said source erable to add moisture to the air in said room; and including in series said damper and said thermostatic means responsive to changes in temthermostat.

perature of said heating coil, and operable when PAUL KOMROFF. heating uid is supplied to said coil to maintain ROBERT D. LAMBERT. a circuit closed, and, upon the failure of the Y MATSON C. TERRY.

supply of heating fluid to said coil, to open said 

